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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>
    <script>
        var sun = 1 + 5;
        console.log(sun);
        var sun1 = '1' + 5;
        console.log(sun1);
        var str = '这是字符串';
        var str1 = '这是字符串';
        console.log(str == str1);
        console.log(str===str1);
        var arr = [1,2,3];
        var arr2 = [1,2,3];
        console.log(arr==arr2);
        console.log(arr===arr2);
        var obj = {
            name:'老王',
            age:16,
        }
        var obj1 = obj;
        console.log(obj==obj1);
        obj1.age = 18;
        console.log(obj==obj1);
        console.log(obj.age);
        var a;
        var b = null;
        console.log(a==b);
        console.log(a===b);
        
    </script>
</body>

</html>